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Reissued Nov. 29, 1932 UNITED STATES PATENT OFFICE nnwm R. LEDERER, OF FORT WORTH, TEXAS, AS SIGNOR TO TEXAS PACIFIC COAIrfi OIL (30., OF FORT WORTH TE XAS, A CORPORATION OF TEXAS LUBRICATING on. .IAND METHOD or rnonucme THE same Io Drawing. Orlg'inal I'm-1,803,941, dated May 5, 1931, Serial No. 844,605, filed March 5, 1929. Application for reissue filed April 16, 1932. Serial No. 605,781.

This invention relates to a method of producing fully dewaxed, unblended paraffin bar" lubricating oil of a cold test of approximately 0 R, such as described and claimed as an article of manufacture independent of its process of manufacture in my copending application, Serial No. 334,607, filed January 23, 1929, which is a continuation in part of my previous application Ser. No. 257,110, filed Feb. 25, 1928, and to the low cold test residual or cylinder stock lubricating oil of high viscosity as produced by the processes herein described, or essentially similar process for cold dewaxing.

The object of the invention is to provide a recess or method for the handling of para n base crude, in this particular instance Ranger crude, as produced in Eastland and Stephens Counties in the State of Texas although applicable to parafiin base crude oil from other localities, so as to effect, during the distilling, refining and purifying operation, the structure of the paraflin base in the manner which is most favorable for complete removal of the paraffin wax constituent, and the production of a low cold test residual or high viscosity lubricating oil.

It is generally conceded that paraffin base oils are best for lubricating purposes as such oils continue to supply the desired lubricating film in automotive engines and machines even when the latter are heated up to relatively high degrees. Paraffin base /oils as produced prior to my invention have, h0wever, had the disadvantage of congealing or failing to flow at temperatures approaching zero Fahrenheit because of the previous impossibility of commercially fully dewaxing parafiin base oils. 4

I have been able to fully dewax paraffin base lubricating oils and am able to produce a pure fully dewaxed unblended and uncompounded paraflin base oil which will be free flowing at temperatures below its cold test and which, in view of its lubricating properties at high temperatures as well, can be used for both summer and winter driving conditions or for aeroplane work, eliminating the necessity for producing and marketing two ing a lower temperature temperature.

a tendency tbbreak up under high operating It is also recognized that the use of unblended lubricating oils having hydrocarbons in the natural order of their occurrence in the crude oil provide a more stable oil, better adapted for use at high temperabetter than the asphalt base oils which have tures than the blended and mixed oils'which have constituents vaporizing range of temperatures. I

While my process, in general, observes the same steps and sequence of steps which are normally followed in ing of lubricating oils, I have found that particular care is necessary not only in the distilling, but in the refining and dewaxing steps to place or preserve the paraffin or wax base in an amorphous condition'in which the same may be fully removed from the oil prior to placing the same on the market.

In substance, I provide an originally residual paraffin base oil by careful distillation, which contains substantially all amorphous wax and then remove the asphaltic and tarry impurities and discolorizing and solid impurities while maintaining the wax in an amorphous condition and then completely remove the waxfrom the oil by chilling and dewaxing.

In manufacturing dewaxed paraffin base lubricating oils accordingto my preferred process during the regular process of distillation, gasoline, kerosene, gas oils, cracking stocks and non-viscous neutrals, etc., are distilled overhead in a'cpntinuous battery of stills or in, specially constructed tubular stills equipped with frac through a wide tionating equipment until in the last still of the refining and purify i or at approximately'the lower range of the (8) hours longer than in ordinary practice' I have found that this lower tem erautre in the distilling operation bringing a out a slow distillation with no tendency to overheat and no cracking or scorching of the oil prevents the formation of a wax having a definite crystalline structure and provides in the last still or the long residuum a bright stock of good green color and sweet odor containing 5 substantially all amorphous wax which can i be, by the subsequent steps described below,.

completely 'dewaxed if care is observed to maintain the wax in its amorphous condition, whereas crude 011 from the same sources,

when subjected to 'a distilling operation in which the stills are maintained at or near the maximum temperature for each particular fraction, often comes from the last still 5 with a crystalline wax formation which submovable 5h decolorizing steps.

sequently defies complete removal from the oil or when carelessly handled, the amor phous wax may be converted into a non-revariety in the asphalt removal or Upon removal from the last still, the bright stockin my'preferred process may be stored and aged from thirty to sixty days at an even temperature in special storage tanks although this is not essential and' is then treated in regulation agitators at a temperature of from 115 to 125 F. with a minimum of 35 lbs. per barrel .of-98% sulphuric acid.

If necessary, the temperature of the oil is vphalt ho reduced, by means of the cooling system, to

115 to 125, or, in winter is raised, by suitable heating means. The low temperature-at which the oil is subjected to the sulphuric I acid or other asphalt removal treatment is a important as it affects the oxidization of the paraflins in the oil, making it easier to controltheir proper solidification when chilling. Temperatures above 120 F. in the presence of acid also affect the solubility of any asbodies in the paraifin, thereby retarding the desired formation of the paraflin which is necessary for proper separation 1n tliile production of low cold test lubricating 'o 55 The sludges including tarry and resinous matter pro ment are drawn from the agitator and the clean" acid oil again pumped to storage where further settling of the sludges is permitted to take place at a storage temperature around The acid oil is then mixed with filtering and decolorizing clay pulp which has. been suitably prepared using .2 pounds or upwards per gallon of oil and the mixture of uced by the sulphuric acid treat- .are no light ends to distill clay pulp and oil is passed through a tubular pipe still heated to 420 F., afterwhich the temperature is reduced to 135 F.,- the oil-pulp mixture diluted with 40% or more ofshort boiling range naphtha to reduce the gravity to 36-38 B. and is then forced through a filter, preferably of the pressure type, to separate the clay from the oil.. The filtered oil is further diluted with an additional of naphtha to produce a gravity of 46-48 B., and the mixture is chilled in special chilling tanks, with special care that the chilling shall be an uninterrupted procedure, reducing the temperature about 2% every hour until a temperature of 10F. above zero is reached. From this point down, the oil is chilled as rapidly asp'ossible and held at a minimum temperature of ''20 to with agitation,

to complete the precipitation of paraflin from I solutidn, so as to permit it to be removed in a single stepv dewaxing operation by mechanical means, tering. trifuged in super centrifuges of the less type, using 4 inch feed nozzles and a ring size of 4:1 to ity of the oil being fed to eifect a' more thoroughly com lete separation of the wax from the oil. wax and the chilled oil may be eflected by passing through a suitable filter. After removal of the wax in this manner, the oil is redistilled at a low temperature, preferably not exceeding. 500 F. with a considerable amount of lowpressure steam to distill oif the blendin naphtha and neutrals, leaving the zero col test fully dewaxed parafiin base such as centrifuging or fil- The mixture is then preferabl cenharp- 1 42 which reduces the veloceparation of the solidified lubricating oil in condition for commercial been produced prior to my production of the I same and satisfies in many ways the ideal I standard for a universal summer and winter lubricating oil which has been set by the aeroplane and automotive lubrication engineers. Being a paraflin base lubricating oil, this new-oil provides for better lubrication at high temperatures, and as the oil is unmixed or unblended paraffin base, there off or be destroyed by the high temperature. As it is fully dewaxed, it is free flowing and can be pumped under normal pump pressures of from 7 to 10 pounds at temperatures even as low as minus 40 F. and therefore provides for proper lubrication at low temperatures. The process, therefore; produces a lubricating oil normal lubricating both summer and winter driving and for aero- 1 been removed, is

which is superior at all temperatures to the oils and may be used for planes in which wide variations in temperature are experienced in a relativelyshort period of time in altitude flights, without the necessity of carryin two grades of oil.

The oil produced as the following characteristics:

1. It is an unblended residuum parafiin .bas'e lubricatin oil.

2. It is comp etely dewaxed, i. e., 'free from wax for commercial purposes.

3. Its viscosity on the Saybolt universal viscosimeter is from '50 at 210 F. to 200- at 210 F. but preferably from 60 at 210 F, to 200" at 210 F. n

4. It will flow at pressures from 7 to 10 lbs. absolute at temperatures from plus 20 F. to minus 40 F.

5. It retains its lubricating properties at higher temperatures and being unblended,

there 1s no tendency of any lighter fractions to distill over at higher operating temperatures. 7

While in general the process I use corresponds to conventional commercial processes in the treatment and preparation of lubricating oils, I do not know any process outside the principles of the one disclosed which will result in a completely dewaxed lubricating oil of a viscosity of at 210 up to 160 at 210, nor is it possible with the ordinary run of bright stock to produce a fully dewaxed paraflin base lubricating oil because in the normal distilling operation without special care exercised in my process, the high temperatures of the still precludes the desiredamorphous condition of parafiin andthe subsequent treatment with sulphuric acid and subsequent chilling will not convert this wax structure into that desired to permit complete removal of the wax from the oil by any known means. While I have described my process and the prefrred method of performing the same with considerable detail, it will be understood sequence of the steps may departing from the spirit the scope of the appended be altered without of my invention or claims.

It will also be understood that the term cylinder stock as used herein, when applied to a finished oil, from which the asphalt, tarry ingredients and discoloring material have synonymous with the trade term Bright stock.

What I claim as my invention is:

1. The method of producing 'a fully dewaxed paraflin base residual lubricating oil having a cold test below 0 F. and a viscosity above 90" at 210 F. from oil from which the lighter fractions have been distilled to rovide substantially amorphous wax in the still due contains wax substantially alliof which is in amorphous form, after ageing from 30 to days at an even temperature with a minimum of 35 pounds per barrel of 98% sulphuric acid at 115 to 125 F., removing the I acid sludge, reheating the oil with a decolorizing clay separating the clay from the oil, diluting t e oil, chilling to -20 to 40 F. to solidify the wax, passing the'chilled oil through said centrifuge to separate the wax from the oil.

3. The method of producing fully dewaxed 0 F. cold test paraffin base residual lubricating oil from crude oil from which the lighter fractions have been distilled at a temperature approximating the lower range of the boiling temperature of the particular fraction to provide a residuum bright stock of green color and sweet odor, containing amorphous wax and substantially free from crystalline wax, which would interfere with centrifugal separation of the wax and oil, which comprises ageing the residuum oil, treating the same with sulphuric acid at 115 to 125 F., removing the acid sludge, storing the oil to permit settling of the acid sludge, treating the oil with clay at a temperature approxlmating 420 F., reducing the tem perature of the clay and oil to 135 F., diluting the oil with naphtha and filtering to remove the clay further diluting the oil, chilling at a rate approximately 2 per hr. to about 10 F. and chilling more rapidly to 20 to 40 below zero, centrifuging the wax from the oil, and separating the diluent from the dewaxed oil.

4. The method of producing fully dewaxed 0 F. cold test paraifin base residual lubricating oil from paraffin base crude oil from which the lighter fractions have been distilled at a temperature approximating the lower range of the boiling temperature of the particular fraction to produce a residual oil containing amorphous wax and substantially below the temperature which would cause conversion of amorphous to crystalline wax, reducing the temperature of the clay and oil, diluting the oil with naphtha and filtering to removing wax from a sion of amorphous to crystalline wax which comprises ageing the still residue, removing the asphaltic and tarry ingredients by sulseconds at 210 the wax phuric acid treatment, removing the discoloring material, diluting the oil, chilling to -'20 to 40 F. to recipitate the wax. centrifuging the wax rom the chilled oil and separating the diluent from the dewaxed 6. The, method of producing a full dewaxed paraflin base oil having a col test below 0 F. and viscosity above 90" at 210 from an originally residual undewaxed base containing amorphous wax and substantially free from crystalline wax which comprises removing asphaltic impurities by" sulphuric acid treatment while maintaining the wax in an amorphous condition, removing solid and discoloring impurities by clay treatment while maintaining the wax in an amorphoiis condition, thinning the oil with a solvent, chilling to F. to F. to congeal the wax, separating the congealed wax from the chilled oil and separating the solvent from the dewaxed oil.

7. The method of fully dewaxing paraflin base residual oil which may be partially dewaxed at higher temperatures which comprises providing a residual oil from which the lighter fractions have been distilled so as to provide substantially all amorphous wax in the'residue, by ageing the residue, treating withsulphuric acid to remove asphaltic and tarry ingredients, treating with decolorizing clay, diluting with a lighter hydrocarbon,.chilling to 20 to -40 F. separating from the chilled oil and distilling o the diluent.

8. The beldw 0 F. cold test dewaxed residual parafiin base lubricating oil, having a viscosity of" at 210 F. to 200" at 210 F. produced from'refined still residue from which the lighter fractions have been distilled so as to provide substantially all amorphous wax in theresidue by treatment of the residue with sul huric acid below 125 F., to maintain the wax in an amorphous condition, treatment with decolorizing clay, diluting and chilling to 20 F. to "40 F., separating the wax from the chilled oil, and separat ing the diluent from the dewaxedpil.

9. The cold dewaxed unblended paraflin base, residual lubricating oil having a viscosity of frdm 50 seconds at 210 F. to 200 F. on the Saybolt universal viscosimeter and a cold test zero to 10 F.

and capable of flowing freely at 7' to. 10' absolute pressure at temperatures as low as 30 F., produced from originally residual cylinder stock containing amorphous .wax and substantially free from crystalline wax by treatment with sulphuric acid to remove tarry and asphaltic ingredients, treatment with filter clay to remove discoloring material, dilution of the oil with lighter hydrocarbons, chilling to 30 to 40 F., separating thev diluent from the dewaxed oil 10. The all season lubricating oil for use in automobile and aeroplane engines, comprising an unblended fully dewaxed paraflin ase residual oil, having a flash point above 480 F. a Saybolt viscosity above 90" at.210 F. and a cold test below zero F. and bein free flowing at pump intake pressures of to 10 lbs. as low as -4=0 F., produced from parafiin base crude oil from which the lighter fractions have been distilled at a temperature approximating the lower range of boiling temperature of the particular fraction to provide a still residue containing wax substantially all of which is an amorphous form, by

treatment of the .still residue with sulphuric acid below 125 F. to remove tarry and asphaltic ingredients, treatment with filter clay to remove discoloring material, dilution of the oil with lighter hydrocarbons, chilling to 30 to -40 F., separating the wax from the chilled oil and separating the diluent from the dewaxed oil. I

11. An all season lubricating oil for uses. in automotive engines, 'comprising an unblended fully dewaxed paraifin base residual oil having a flash point above 480 F. a Saybolt viscosity offrom 88" at 210 F. to 155" at 210.F. and a coldtest of from zero to 15 F. and being free flowing at pump intake pressures of 7 to 10 lbs. as low as 40 F., roduced fromparaifin base crude oil from whlch the lighter fractions have been distilled to provide a still residue containing waxsubstantially all of which is an amorphous form, by treatment of the still residue with'sulphuric acid below 125 F. .to remove tarry and asphaltic ingredients, treatment with filter clay to remove discoloring material, dilution of the oil with lighter hydrocarbons, chilling to below 20 F.,-centrifuging the wax from the chilled oil and separating the diluent from the dewaxed oil.

12. The low cold test unblended paraflin base lubricating oil free of wax, having a viscosity of from 50 seconds at 210 F. to 200 seconds at 210 F. on the Saybolt universal viscosimeter and a cold test of zero to 10 F. prepared from an originally residual stock containing amorphous wax and substantially free from crystalline wax by treatment of the residual stock to remove tarry and asphaltic ingredients by steps'equivalent to acid treatment while maintaining the wax in an rating the wax from the chilled oiland sepaamorphous condition, treatment with filter ing the diluent from the dewaxed oil.

a viscosity above 90" at 210 13. The below 0 F. cold test dewaxed unblended paraflin base lubricating oil having F. produced from an original residual undewaxed base containing amorphous wax and substantially free from crystalline wax by removing the asphaltic and tarry impurities by sulphuric acid treatment while maintaining the wax in an amorphous condition, removing solid and discoloring impurities while maintaining the wax in an amorphous condition, thinning the oil with 'a solvent, chilling to -20 F. to 40 F. to congeal the wax, separating the congealed wax from the chilled oil and separating the solvent from the dewaxed oil.

14. The method of producing a dewaxed 0 F. to 10 F. cold test finished lubricating oil having a viscosity of 50" to 200 at 210 F. from the residual cylinder stock of paraflin base crude oil in a single stage de-. waxing operation which comprises removing the asphaltic and, tarry ingredients by aci treatment, removing the discoloring material, thereafter diluting. and chilling the oil to 20 to 40 F. to precipitate the wax, centrifugally separating the wax from the chilled oil and separating the diluent from the dewaxed oil.

15. The method of fully dewaxing paraifin base oil of cylinder stock characteristics to substantially 0 F. cold test which comprises providing an oil of cylinder stock characteristics from which the lighter fractions have been distilled so as to provide substantially all amorphous wax in said oil, removing asphalt'ic and tarry ingredients by acid treatment, treating with decolorizing clay, there after diluting with a lighter hydrocarbon, chilling to 20 F. or below centrifugally separating the wax from the chilled oil and distilling off the diluent.

16. The method of producing a dewaxed paraffin base residual oil having a cold test of substantially 0 F. from an originally residual undewaxed base containing amorphous wax and substantially free of crystalline wax which'comprises providing a residual oil from which the lighter fractions have been distilled so as to provide substantially all amorphous wax in the residue, removing the asphalt and tarry impurities by acid treatment, removing the discoloring material thereafter thinning the oil with a solvent, chilling to 2 0 F. to 40 F. to congeal the wax, separating the congealed wax from the chilled oil and separating the solvent from the dewaxed oil. i

17. A low cold test finished paraifin base residual lubricating oil from 50 seconds at 210 F. to 200 seconds at 210 F. on the Saybolt universal viscosimeter,

single dewaxed lubricating oil having a viscosity of from 50 seconds at 210 200 seconds at 210 F. on the Saybolt universal viscosimeter and a cold test without blending of zero to 10 F. and prepared from an originally residual stock in which the wax is sufficiently amorphous for removal by centrifugal separation when precipitated 'by chilling, by removal of the asphalt, tarry and .discoloring material by acid and clay treatment thereafter diluting, chilling to preci itate the wax and centrifu ally se arating t o' precipitated wax fromt e chi ed solution of the oil.

18. A low cold test, dewaxed, natural, un-

blended, residual lubricating oil having a viscosity of 50" to 200 at 210 F. and a cold test of -15 to plus 10 F. produced from an original-undewaxed residue in which the wax is in sufliciently amorphous form for centrifugal removal when precipitated by chilling, by removal of the asphalt, tarry and discoloring' materials by acid and clay treatment thereafter diluting the residue with a. solvent, chilling the solution to'a temperature between -20 F. and 40 F. to precipitate the wax and centrifugally separating the precipitated wax from the chilled solution of the oil.

19. A low cold test, dewaxed, unblended,-

natural paraffin base lubricating oil having a cold test of 0 F. to 10 F. and a viscosity of 7 0" to 200" at 210 F. .which' is obtained from wax-containing petroleum of cylinder stock characteristics in which the wax originally present is in sufliciently amorphous form for continuous centrifugal removal when precipitated by chilling, produced by first removing the asphalt, tarry and discolor-ing materials, by acid and clay treat- -ment thereafter diluting, chilling to precipiv tate the wax, centrifugally removing the precipitated wax from the chilled solution of the-,oil and removing the diluent from the dewaxed oil.-

, 20. A cold dewaxed unblended paraflin base having a viscosity of a cold test of 0 to 10 F. and capable of flowing freely at 7 to 10 lbs. pump intake pressure at temperatures as low as minus 30 F. produced .by purifying the residue, clay treatment thereafter, diluting, chilling to -20 to 40 F. to congeal the wax, centrifugally separating the congealed wax from tlfie dilute oil and separating the diluent from t e oil. 1

.21. A low cold test unblended paraflin base lubricating oil free of wax, having a viscosity of from 50 seconds at 210 F. to 200 seconds at 210 F. on the Saybolt universal viscosimby acid and eter and a cold test of0 to 10 F. prepared and tarry ingredients by acid treatment, reoil in one dewaxing step, and separating the moving the discoloring material, thereafer diluent from the dewaxed oil. v diluting, chilling to congealthe wax, sepa- In testimony whereof, I have ailixed my. rating the congealed wax from the chilled signature to this specification. f

5 'oil by difference in specific gravity and sepa- ERWIN R. LEDERER. rating the diluent from the 011.

'22. An 11 season lubricating oil for uses in automotive engines, comprising an unblended full dewaxed paraifin base oil-of cylinder stoc characteristics, having a flash point above 480 F., a Saybolt viscosity of from 50" at 210 F. to 206" at 210 F. and'a cold test offrom zero to F. and being free flowing at pump intake pressures of 7 to 10 15 lbs.,as low as minus F. produced from a 8o cylinder stock fraction by removal of the asphalt, tarry and discoloring materials, by acid and clay treatment thereafter diluting, chilling to precipitate the wax, separating the zoprecipitated wax from the chilled oil and 85 1 separating the diluent from the dewaxed oil.

23. A series of dewaxed paraflin base cylinder stockv lubricating oils having in their unblended condition viscosities from see- 25 onds at 210 F. to 200 seconds at 210 F. on G" the Sa bolt universal viscosimeter and cold testsv 0 approximately 0 F. and capable of flowing freely under pump pressures at temperatures as low as minus 30 F. produced from an oil of cylinder stock characteristics 5 byremovin asphalt, tarry and decoloring V ingredients y acid and clay treatment, thereafter thinning the oil with,a solvent, chilling to -20 F. or below to congeal the wax, sepa- Sii'rating the congealed wax from the chilled oil by difference in specific gravity and separating the solvent fromthe dewaxed oil. 24. A series of paraflin base residual cylinderstock lubricating oils having in their un- 40 blended condition viscosities of from 50 sec onds at 210 F. to 200 seconds at 210 F. on the Saybolt universal viscosimeter and cold tests of minus 15 to nlus10 F. produced from parafiin base cylinder stocks by remov ll ing asphalts and discoloring material, by acid 11o,

and claytreatment thereafter diluting with i naphtha, chilling the diluted oil to 20 F. or below to congeal the wax, separating the congealed wax from the chilled oil by difier- 50 ence in specific gravity and reducing the oil to the desired viscosity and cold test. I

'25. Aseries of single dewaxed paraflin base cylinder stock lubricating oils of 0 cold "test and viscosities of 7 0"- to 200 at 210 F. produced from a finished oil of cylinder stock characteristics, which has been distilled so as to provide an amorphous wax in the stock and from which the asphalt, tarry and disj coloring materials ,have been removed by m steps...equivalent-to acid and clay treatment while still maintaining the wax in amorphous cqndition by diluting said stock, chilling to approx mately 40 F. to congeal the wax, I separating the congealed wax from the chilled no 

